The Neutrino Oscillation Industry*d.umn.edu/~vvanchur/2013PHYS1021/gran.pdf · PDF...

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Transcript of The Neutrino Oscillation Industry*d.umn.edu/~vvanchur/2013PHYS1021/gran.pdf · PDF...

  • The Neutrino Oscillation Industry*

    *Title taken from Maury Goodman's websitewww.neutrinooscillation.org

  • Funny math bit you may not have thought aboutsin2

    is NOT just for angles and trigonometry,waves and other oscillating functions

    and doesn't have to be a function of kx or t.

    It is also can be used to represent a constantwhose value must be between 0 and 1

    which is a property it shares with a probability.

    Furthermore, this constant automatically includesits probability partner (1 P) = (1 sin2) = cos2

    So we could use either sin2 or just as a constant of nature driving either/or probability.

  • Standard Model of Elementary Particles

  • What does a neutrino look like in our detector?

    distance along beam axis36 cm

    Strange question.How does an electron look? Proton? Gold nucleus?

    Question: if we build experiments to detect neutrinoswhat will we see?

    Neutrino interaction, May 2010from MINERvA experiment data

  • A picture of a typical neutrino interaction

    muon neutrino muon

    muon from pion decaypion

    Carbonnucleus

    v + n - + + + nbut neutral particles are unseen muon

    pion

    The neutrino turned into a muon, and made a pion

    distance along beam axis36 cm

  • A picture of a typical neutrino interaction

    muon neutrino muon

    muon from pion decaypion

    Carbonnucleus

    v + n - + + + nbut neutral particles are unseen muon

    pion

    The neutrino turned into a muon, and made a pion

    distance along beam axis36 cm

  • New Standard Model?

    + string theory?+ extra dimensions? missing Higgs particle?+ higher order group theory?+ Branes?+ New particles?+ New forces?+ Quarks not fundamental?+ Sub-structure to electron?+ Theory of Everything?+ Theory of Almost Everything?

    How do we tell which are right?Or are they all science fiction or fantasy?

  • New Standard Model: Concrete Example1012

    109

    106

    103

    1

    10-3

    Higgs particle above this line is standardSupersymmetry particle?Super-massive Right-Handed Neutrino?quarks

    charged leptons

  • Standard Cosmology

  • Post-modern Cosmology

    Nobel Prize >2020 ?

    Nobel Prize >2030 ?

  • Matter-Antimatter asymmetry (CP violation)

    How to explain that our region of the universeseems to be nearly all matter, not anti-matter?

    Actually there is a second boxwith anti-electrons (positrons)anti-up and anti-down quarks

    and so on. We know these well.They are perfect opposites,

    but actually not quite perfect!

    But my shoes are not madeof anti-electrons.

    My kids aren't made ofanti-protons and anti-neutrons.

  • Curious things about Quantum TheoryThat are important for the rest of the story.

    A non quantum example of a quantum phenomenon.

    Three ice creams.

    You can describe them in terms of flavor:Strawberry, Vanilla, Chocolate.

    You can describe them in terms of color:Red, White, Brown.

  • Curious things about Ice CreamsThat are important for the rest of the story.

    Flavor comes from a perfume factory in New JerseyColor comes from a differentchemistry factory elsewhere in New Jersey.

    Red does not have to taste like chocolate.There is no reason to think Vanilla won't be brown.

    Quantum mechanics, particle physics standard modelAllow mixups like this to happen.

    Experimentally figure out what New Jersey is doing!

  • More curious things about Ice CreamHypothesis: Darker colored ice cream will melt faster (decay)

    regardless of its flavor.

    We could start with 1 million ice creams, each is one combinationof color and flavor and take a two separate surveys:

    1/3 S; 1/3 V; 1/3 C and also 1/3 W; 1/3 R; 1/3 B

    Now all the brown ones melt away, and we look at whats left. 1/4 S; 1/2 V; 1/4 C and also 1/2 W; 1/2 R

    If this is what New Jersey delivered, this is what you get...conclude that Brown was made of half strawberry, half chocolateYou know this by the deficit of S&C but no deficit of Vanilla!

    Measured the flavor of a sample of many ice creams as a function of TIME (before and after)

    for ice creams that are just sitting there minding their own business.

  • More curious things about NeutrinosThe physics of neutrinos is NOT the physics of melting or decaying.

    It is the physics of superposition and interfering waves.

    A neutrino oscillation experiment creates neutrinos as a flavor.

    Experiments taste flavor.

    But each neutrino also has one of three masses

    (mass, not color!)

    and the folks in New Jersey naturejumble flavor and mass

    according to some secret formula.

  • Probability( to ) = sin22 sin2(1.27 m2 L/E)units: L in km, E in GeV, m in GeV/c2

    m22 - m32

    Measure L and E for each eventFit two parameters to the whole group of data.

    Look for disappearance of muon neutrinos

    Amplitude of maximum tauJust a number 1.0

    IS NOT an oscillating term

    Where in (travel Length)/(Energy)

    does maximum tau occur?Really these are proper

    oscillations in TIME

    The secret formula!

    If we create mu flavor

  • Neutrino detection

    We detect things at Soudan with 5 thousand tons of instrumented iron. This device can see very well and e sorta okay

  • Neutrino flavor change

    We produce and detect e and .Previous experimental results (1998, 2005) suggest:

    1. this experiment will see fewer than we sent.AND

    2. this experiment will see zero or almost zero e.

    BECAUSE Some of the changed to .

    Remember: Ice cream melting does not do this, but quantum mechanical particles can do this.

  • Neutrino oscillations: MINOS experiment

    Situation: We create at Fermilab with a machine that only creates .

    Send them through the earth to Soudan, MN.The L in our formula is 735 km

    (really 2.5 milliseconds traveling at the speed of light).

  • How does MINOS see neutrinos?

    We don't see the neutrinos themselves

    We see the result of their interactionwith rock, steel, or plastic.

    They communicate flavornot by tasting them:

    a muon neutrinoproduces a muonin the interaction

    We count muons.We count muonsreally, really well.

  • How does MINOS see muons?

  • Photo of ascintillator strip

    41 mm10 mm

    Cross-section photo of two scintillator strips with fibers glued into grooves.

    Scintillator graphicscourtesy of Doug Michael, Caltech

    Ionization produces light in scintillator

    Fiber optics route light to a set of light sensors

  • High Voltage in, electrical pulse out

  • Thousands of pulses all come together here

  • Fermilab beam ->

    Ask a computer to reconstruct it all.Side view Front (Fermilab) view

    This one started in rockproduced a muon

    which went into the front of detector

    and stopped 2/3 through

  • What MINOS sees after four years of beam

  • What MINOS sees after four years of beam

  • Ratio of data to red prediction and best fit

  • What MINOS sees with the best fit to the formulaWhere in energy

    the maximumeffect is seentells us aboutthe oscillating

    term and (m2)

    How deep themaximum effecttells us about theamplitude term

    sin22

    Probability( to ) = sin22 sin2(1.27 m2 L/E)units: L in km, E in GeV, m in GeV/c2

  • Higher E

    Wherein Energy Is the dip

    Lower E

    How deep is the dip?Shallow Deep

    What we measure for nature's parameters

  • More about particle masses1012

    109

    106

    103

    1

    10-3

    quarks

    charged leptons

  • We could see electrons instead of mu or tau? The secret formula assumes mu to tau oscillations

    because nobody had seen mu to electron oscillationsso this is either very rare, or it never happens

    The oscillation hypothesis says it could (should?)

    MINOS is able to seeelectrons, sorta.

    In fact, we expect someelectron like things

    even without oscillationsbecause the beamisn't actually pure.

    And even still, we seeextra! Sorta.Electron-like events in MINOS

  • Next steps in neutrino oscillations: NOvAMINOS is barely able to search for electron appearance

    NOvA is optimized for this search and/or measurement.Located in Ash River, Minnesota

    Hmm. T2K in Japan is a competing experiment

  • Next steps in neutrino oscillations:LBNE and search for CP violation

    Radically different detector technology.Longer baseline. More powerful beam.

    Combine numu disappearance, nue appearanceOptimized to look for differences between

    neutrino oscillations and anti-neutrino oscillations

  • How can we see that this is maximally odd?no mixing at all.zero sin22 for all threecombinations 12 13 23

    slight mixing among allall sin22 slightly above zero

    full mixing among allall sin22 very close to 1

    two mixings are maximaltwo sin22 are slightly less than oneand the other is slightly more than one

  • How can we see that this is maximally odd?no mixing at all.zero sin22 for all threecombinations 12 13 23

    slight mixing among allall sin22 slightly above zero

    full mixing among allall sin22 very close to 1

    two mixings are maximaltwo sin22 are slightly less than oneand the other is slightly more than one

    BORING

  • How can we see that this is maximally odd?no mixing at all.zero sin22 for all threecombinations 12 13 23

    slight mixing among allall sin22 slightly above zero

    full mixing among allall sin22 very